1. Field of Invention
The present invention relates to opacifying materials. In particular this invention relates to water-dispersible microgranular protein opacifying materials which are suitable for use in food products, processes for their manufacture, and methods of use.
2. Statement of Related Art
Continuing public demand has led to ongoing efforts to develop new food products with suitable taste and appearance. A product which does not have an expected appearance may not even be purchased from a grocery shelf. Even if purchased, a product which imparts an unusual visual perception may be unfavorably received, even if its other organoleptic properties are acceptable. Duplication of opacity, creaminess, and whiteness is especially important in products which try to mimic cream and cream-like materials.
Titanium dioxide, which is a classic whitener for paints, can be a very effective opacifier and whitener for food products. Although considered safe in food products, titanium dioxide is an inorganic additive which by its very nature would be expected to find decreasing favor with greater public awareness of food additive contents.
Additionally, the brilliant whiteness of titanium dioxide is not necessarily desirable for mimicking the off-white creamy color desired for many food products. Resorting to artificial colors to correct this problem would be expected to compound the problem of public acceptance.
The use of opacifiers derived from protein materials would be expected to alleviate consumer acceptance problems especially if the materials are derived from readily identifiable and acceptable "natural" sources.
Singer, U.S. Pat. No. 4,734,287, discloses a proteinaceous water-dispersible macro-colloid comprising substantially non-aggregated particles of heat denatured whey protein coagulate having particle size distributions of about 0.1 microns to 2.0 microns. The macro-colloid may be produced by controlled or extent limited denaturation of whey protein concentrate with very high shear. The macro-colloid is suggested as I5 lacking utility for high temperature applications due to the extent limited denaturation. Singer additionally indicates that mechanical size reduction of proteins does not produce acceptable protein material for incorporation into food products.
Singer, U.S. Pat. No. 4,985,270, discloses food products containing proteinaceous water-dispersible macrocolloids, wherein a preferred protein is dairy whey.
Petrowski, U.S. Pat. No. 4,045,589, discloses a coffee whitener prepared without the use of protein by incorporating modified dextrinized starch in an aqueous emulsion containing fat or oil and a conventional emulsifier.
Burge, U.S. Pat. No. 3,852,506, discloses a dispersible whey protein composition prepared from demineralized and delactosed whey protein which is spray dried, and then ground in a hammermill or similar mill using hammer- or knife- milling action to obtain particles of which at least 55% are less than 44 microns. The particles are subsequently agglomerated.
Hakkaart, published European Patent Application No. 412590, discloses a heat denatured protein in the form of microcolloidal particles having a mean size in the o range of 0.1 to 10 microns in which the .alpha.-lactalbumin to .beta.-lactoglobuline ratio is greater than 0.43. The heat denatured protein is prepared by successively heating and concentrating whey protein concentrate at neutral pH.
Rialland, U.S. Pat. No. 4,782,138, discloses a process for separating .alpha.-lactalbumim from whey by heat treating the whey at a pH less than 4 and recovering the precipitated .alpha.-lactalbumin.
Pisecky, U.S. Pat. No. 4,490,403, discloses a process for spray drying whey and added fat.